Background: Allergic rhinoconjunctivitis (ARC) is an allergic upper respiratory tract disease characterized by sneezing, runny nose, nasal congestion and ocular and nasal itching due to inflammation of the nasal and conjunctival mucosa. There are no studies evaluating both the choroidal and retinal areas in ARC patients. Our objective was to evaluate patients with ARC at the time of diagnosis and before initiating treatment using Optical Coherence Tomography (OCT). Methods: This prospective cross-sectional study included 30 patients with ARC who presented to the Pediatric Allergy & Immunology Outpatient Clinic and 30 healthy control individuals. OCT scans were captured with Cirrus HD OCT-5000 (Carl Zeiss, Jena, Germany) in the enhanced depth imaging (EDI) mode. Results: Of the study population, 66.7% (n=20) of patient group and 56.6% (n=17) of control group were female. The mean age was 13±2.3 and 13.9±1.8 years in the patient and control groups, respectively. The temporal subfoveal choroidal thickness was statistically significantly thinner in ARC patients with asthma (p=0.032). A robust negative correlation was found between minimum ganglion cell-inner plexiform layer (GCIPL) thickness and allergic eosinophil count (AEC) in patients with ARC (r: -0.551, p<0.0001). Conclusion: In our study, the GCIPL thickness was lower in ARC patients. Similarly, although it did not reach statistical significance, the minimum GCIPL thickness was lower in our patient group with asthma compared to those without asthma. Our results suggest that multiple allergen sensitization and elevated eosinophils may influence GCIP thickness. However, both choroidal and retinal tissue might be impacted during chronic follow-up. Further studies are needed to support these findings. Keymessage: Multiple allergen sensitization and elevated eosinophil levels contribute to GCIPL thickness in ARC patients.